338 Ultra Mag Info

[benny1]

I also love the 338 rum I ran rl33 in a ladder with 300 gr Sierra
I started at 97 grs 2815
98 grs 2820
99 grs 2854
100 grs 2901
101 grs 2898
102 grs 2940
103 grs 2929
104 grs 2966
105 grs 3006
106 grs 2999
107 grs 3087
At 100 grs it's starting to b a compressed load no pressure signs
At 104 primers started to flatten out
At 107 stop bad pressure
It was very weird running such a compressed load but I wanted to c where it showed pressure so I backed it down to 105 and it shot a ragged hole at 100 yards 3 shots where 3009, 3016, 3026 the primers were a little flat but it shot well so I backed it down to 103 and shot 2 3 shot groups 2977,2994,2995 and 3008,3004,2998 and it shot 2 prefect triangles all three touching everything was good since I was playing around I went back to 100 where it started to compress and shot a 3 shot group 2882,2902,2896 2 were touching and the 3 rd was about 1/2 inch out
My gun really likes. 105 but since I showed bad pressure at 107 I think I'm not going to shoot it there I think 103 is where I need to b
When loading for ladder test I had to keep turning my mirco seating down in order to keep my oal which is 2.990 off the oglive necked sized 3/4 with a .64 bushing and cases trimmed to 2.741.5 barrel length 28.5
Rl 25 I was at 89 grs @ 2830 and it shot a ragged hole there with no pressure signs
So now I'm off to work again so when I get back I'll play some more with rl33 cuz I like this powder more speed less pressure signs I don't have to be that fast as long as it is easy on gun, primers and barrel after all it just comes down to a few clicks on the scope hope this helps ben

 

[Dick Tinsley]

3000fps with a 300 grn bullet! That's impressive! Even though my 338 RUM likes H-1000, I've got a pound of RL-33, just might try it! Thanks for the info.

DT

 

[USCGLongBow]

Since I have RL33, I am going to try it out with the Berger 250. I just looked at Alliant's website, and they list a max charge of 106 grains with a 250 gameking and a 3.59 OAL. Can anybody recommend a safe starting charge? Right now I was just planning on 100 grains to break in the barrel and get a feel for the gun, and then move up from there. Do you guys have different advice here? I've got GM215M primers and Nosler brass, and planning on starting the bullet .005 from the lands, obviously not exactly sure what that OAL will be until I get the rifle, but it's going to be longer than 3.59. Never reloaded for any RUM case, so this huge case capacity is new to me. Should I go lower than 100 grains?

If it were me I would start at 100 or 101gr and work up a grain at a time. I'm going by the 106 from the Alliant website, and I just always reduce by a little till I'm sure it works in my gun. My guess, based on experience with Berger and similar weighted bullets I shoot in other calibers, is that you will be able to use 106gr with out pressure issue if you want to. I don't want to load to 106gr because you are running out of room in the neck at that point, so for my use I'm stopping at 105gr of RL33 in all my 338RUM loads. I haven't played with RL33 with anything heavier than 200gr Nos BTs yet, but I picked up a box of 265gr LRX today, and will probably load and test next week.

 

[Timber338]

Thanks guys! All off this is great info. I think to be ultra safe, I will back off to 98 grains of RL33 just for the first 10 shoot-clean-shoot-clean break-in shots.

Then increment from there for an initial velocity/pressure ladder. You all have mentioned that RL33 is not ideal (too slow) for the 250 grain pills, but I'm at least going to give it a try. Always a game to find the most accurate combination of seating depth and powder charge, but I'm hoping the 250 Elite Hunter with its hybrid design is less sensitive to seating depth than the classic Berger VLD's. Will still be a couple months before I get the rifle ready to shoot, but I'll make sure to post up my results. I have a couple of pounds of RL25 as well so will be fun to compare.

 

[Timber338]

If it were me I would start at 100 or 101gr and work up a grain at a time. I'm going by the 106 from the Alliant website, and I just always reduce by a little till I'm sure it works in my gun. My guess, based on experience with Berger and similar weighted bullets I shoot in other calibers, is that you will be able to use 106gr with out pressure issue if you want to. I don't want to load to 106gr because you are running out of room in the neck at that point, so for my use I'm stopping at 105gr of RL33 in all my 338RUM loads. I haven't played with RL33 with anything heavier than 200gr Nos BTs yet, but I picked up a box of 265gr LRX today, and will probably load and test next week.

Just read this. Gotcha on starting at 100 or 101. I agree that based on Alliants website that 106 is going to be a safe pressure with a 250 bullet. So starting at 100 or 101 will be a good starting charge. I am hoping 33 works well in my rifle only because I have so much of it. The RL25 I would like to save for the sub 3/8 moa load I already have worked up for my 300 win mag. So I won't move to the RL25 in the 338rumm unless RL33 is not performing. I am actually expecting that 33 is going to work very well. But time will tell...

 

[D.Camilleri]

Sorry I jumped into this so late, but here is my take. I started loading with H-1000 years ago with 225 accubonds and wasn't impressed with velocity. I could only get around 3100. I changed to reloader 25 and 97 grains yielded 3300 fps with the 225 accubonds. I tried some 225 barnes tipped triple shocks and had to reduce the charge to 95 grains and right at about 3200 fps. My barrel is a broughton 5c with a 9.3 twist finished at 27 1/2 inches. Then I had a friend try a newer batch of H-1000 with 300 grain match kings and his velocity was much higher than what I experienced years before. I bought some of the new H-1000 and now with 97 grains and the 225 accubond, I am getting 3300, duplicating my reloader 25 velocity with better temperature stability! Next, I moved up the the 300 gr berger otm hybrid and found a sweet spot with 90 grains of H-1000 and it is yielding 2830 fps.

 

[Timber338]

Sorry I jumped into this so late, but here is my take. I started loading with H-1000 years ago with 225 accubonds and wasn't impressed with velocity. I could only get around 3100. I changed to reloader 25 and 97 grains yielded 3300 fps with the 225 accubonds. I tried some 225 barnes tipped triple shocks and had to reduce the charge to 95 grains and right at about 3200 fps. My barrel is a broughton 5c with a 9.3 twist finished at 27 1/2 inches. Then I had a friend try a newer batch of H-1000 with 300 grain match kings and his velocity was much higher than what I experienced years before. I bought some of the new H-1000 and now with 97 grains and the 225 accubond, I am getting 3300, duplicating my reloader 25 velocity with better temperature stability! Next, I moved up the the 300 gr berger otm hybrid and found a sweet spot with 90 grains of H-1000 and it is yielding 2830 fps.

Curious if you are getting compressed loads with H-1000? RL33 is intense with how compressed the loads get, and the Redding competition dies I have specify not to compress loads or you can damage the seating die.

 

[D.Camilleri]

My loads with H-1000 are only slightly compressed. I would like to try some reloader 33 to see if I am leaving any velocity on the table.

 

[Dick Tinsley]

My loads with H-1000 are only slightly compressed. I would like to try some reloader 33 to see if I am leaving any velocity on the table.

Plus 1. I'm using 99grn of H-1000 with a 250grn NAB. Just a tick over 3100. I also would like to try RL 33 just to see what the differants is.

DT

 

[Timber338]

Plus 1. I'm using 99grn of H-1000 with a 250grn NAB. Just a tick over 3100. I also would like to try RL 33 just to see what the differants is.

DT

3100 fps with a 250 creates some impressive energy.

since you have to compress RL33 so much, and because my Redding competition dies can get damaged with compressed loads, I found a Hornady 338 seating die on sale at Midway that I bought to make some compressed loads. I also have some H1000 and will compare to RL33.

 

[Dick Tinsley]

Timber338
You are right, 3100 with a 250 grn is impressive!(Fun Too)!! I've had a pound of RL33 for awhile, but no data for it. Really don't know where to start. My 338 ultra nor only likes H-1000, but is also fond of Retumbo too. Can't find any Bergers to shoot down here, but the NAB are performing well.

DT